1. Field of the Invention
The present invention relates to a musical performance processing apparatus for controlling musical tone generation based on performance information, and a storage medium in which a musical performance processing program is stored.
2. Description of the Related Art
Heretofore, in an electronic piano or other electronic keyboard musical instrument, various functions have been provided that are useful for practice of musical performance.
For example, a function for use with music data including two tracks respectively stored with right- and left-hand parts is known that enables a user to select whether each part should be played by himself/herself or automatically played by an electronic piano (“Clavinova CVP-309/307/305/303 Quick Guide”, PP. 19-22, Yamaha Corporation, [searched on Mar. 9, 2007], Internet <URL: http://www2.yamaha.co.jp/manual/pdf/emi/japan/cla/cvp309j2.PDF>). With this function, the user is able to select the right- or left-hand part and practice the selected part.
Also known is a function for use with a keyboard divided into left and right key ranges by a split point, the function being for automatically playing a chord whose fundamental tone is specified by depression of a key in a lower pitch key range on the left side with respect to the split point and for enabling a performer to play a desired phrase with keys in a higher pitch key range on the right side with respect to the split point (“Clavinova CLP-240/230 Owner's Manual”, PP. 26-27, Yamaha Corporation, [searched on Mar. 9, 2007], Internet <URL:http://www2.yamaha.co.jp/manual/pdf/emi/japan/cla/clp240_ja_om.PDF>).
There is also known a so-called any-key function or follow lights function, which is for temporarily stopping the reproduction of music data upon arrival of timing in which a keyboard is to be played and for proceeding with music data reproduction when any of keys or a designated key is played (“Clavinova CVP-305/303 Owner's Manual”, P. 99, Yamaha Corporation, [searched on Mar. 9, 2007], Internet <URL: http://www2.yamaha.co.jp/manual/pdf/emi/japan/cla/cvp305j1.PDF>). With this function, a user is able to play music data by repeatedly depressing a key in exact timing, and therefore, is able to practice hitting the keyboard in proper timing or hitting a correct key of the keyboard. With the aid of this function, the user can practice the right-hand part while causing the left-hand part to be automatically played, or vice versa. Of course, the user can simultaneously practice both the right- and left-hand parts using this function.
The applicant or assignee of this application has proposed a system that enables a user to control the reproduction of stored music data by simply depressing (tapping) an arbitrary key at a constant rhythm (Japanese Laid-open Patent Publications Nos. 2007-93820 and 2007-93821).
In the case of using an ordinary piano, a teacher must be capable of playing the piano to perform piano accompaniment for student's practice. When a student practices the left- or right-hand part separately on an ordinary piano, another part is not played or must be played by a teacher capable of playing piano. Thus, a person not capable of playing piano is difficult to perform piano accompaniment in duet for student's practice, and a student is difficult to practice the left- or right-hand part separately.
According to the above described prior art, when a student separately practices the left- or right-hand part on an electronic piano having an automatic performance function, another part is simply automatically reproduced. Thus, the student must perform the practice in time with the mechanical automatic reproduction. In addition, even if the student breaks down, becomes slow, or makes a mistake in the midst of his/her practice, the automatic reproduction goes ahead without waiting for user's performance, which can hinder good practice.
The follow lights function and the any-key function are intended for self-learning use and hence not suitable for teaching assistance use. Unless a musical performance is played exactly in tempo set beforehand, the musical performance is not regarded as accurate, and therefore, the resultant musical performance becomes monotonous, which hinders the performer to develop his/her expressive power. If the musical performance is not played in correct timing, the reproduction of music data is temporarily stopped, which poses a problem that the performer is difficult to grasp the tempo of playing the music.
In sometime cases, the teacher gives lesson while singing a phrase which the student should play. If the reproduction of music data is temporarily stopped during the lesson, the teacher is difficult to proceed with the lesson while singing, which poses a problem.